//封装倒计时函数
import { computed,  onUnmounted, ref } from "vue"
import dayjs from "dayjs"
export const useCountDown = () => {
  //1.响应式数据
  let timer = null
  const time = ref(0)
  //格式化时间 为 xx分xx秒
  const formatTime = computed(() => {
    return dayjs.unix(time.value).format('mm分ss秒')
  })
  //2.开启倒计时的函数
  const start = (currentTime) => {
    //开始倒计时的逻辑
    time.value = currentTime
    timer = setInterval(() => {
      time.value--
    }, 1000)
    if(time.value === 0){
      clearInterval(timer)
    }
  }

  //组件销毁时清除定时器
  onUnmounted(() => {
    if (timer) {
      clearInterval(timer)
    }
  })
  return {
    formatTime,
    start
  }
}
